<!DOCTYPE html>
<html>
<head lang="en">
  <meta charset="UTF-8">
  <title></title>
</head>
<body>

<ul>
  <li>78</li>
  <li>55</li>
  <li>63</li>
  <li>98</li>
</ul>

<script src="js/jquery-1.11.3.js"></script>
<script src="js/6.js"></script>
<script>
  //调用jQuery对象函数——插件函数
  console.log(  $('ul li').max()  );
</script>
</body>
</html>